"New messages" count for Thunderbird on Taskbar

I would like to see the "new messages" count number on my taskbar, like Google Mail, for example something like: Inbox(2) - Mozilla Thunderbird I found FireTray, but it doesn't quite work, the taskbar remains unchanged even when I have new messages: Is it possible to have count number like GMail? I am using Ubuntu 16.04.4 LTS, Xenial with KDE and Thunderbird version 52.6.0.